The company is looking for up to 250 testers from those who sign up at their site, and the open beta begins May 18.

In Poseidon, players build and rule the fabled cities of Atlantis, a kingdom of science and technology. They will mine the mysterious mineral "orichalc," establish colonies in ancient Americas, Africa, Europe, and Asia, and trade with ancient civilizations. New industries, massive monuments, and characters unique to Atlantis expand the city-building experience presented in Zeus: Master of Olympus. Never-before seen gods, monsters, and heroes help tell the tale as players build Atlantis into a mighty kingdom. Players will also be able to create their own adventures in Greece or Atlantis with the game's Adventure Editor.

To be a tester, you must already own the North American version of Zeus: Master of Olympus. Impressions will then pick testers according to a variety of criteria, including your system specifications, experience with Impressions products, and "skill in documenting suggestions and communicating them clearly," according to the company.

Beta testers will receive not only pre-release builds of the game for testing and evaluation, but also boxed copies when the game is finished. Those chosen for the test will be notified on May 1, and required to sign and return a standard Non-Disclosure Agreement.